uboot-mediatek: support classic uImage.FIT with internal images in imszb

The side-effect and main motivation is to also drop the FIT structure size
limit because with multiple device tree overlays it may easily grow beyond
the previous 4kB limit in the future.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
(cherry picked from commit 98e3f82c3f)

package/boot/uboot-mediatek/patches/200-cmd-add-imsz-and-imszb.patch

@@ -70,7 +70,7 @@
  {
 --- a/boot/image-fit.c
 +++ b/boot/image-fit.c
-@@ -2051,6 +2051,50 @@ static const char *fit_get_image_type_pr
+@@ -2051,6 +2051,49 @@ static const char *fit_get_image_type_pr
  	return "unknown";
  }
  
@@ -89,9 +89,8 @@
 +
 +	hdrsize = fdt_totalsize(fit);
 +
-+	/* simple FIT with internal images */
-+	if (hdrsize > 0x1000)
-+		return hdrsize;
++	/* take care of simple FIT with internal images */
++	max_size = hdrsize;
 +
 +	images_noffset = fdt_path_offset(fit, FIT_IMAGES_PATH);
 +	if (images_noffset < 0) {